We’ve had a great time playing Invisible Sun for about the last 3 years. The rules are narratively focused, and heavily driven by the PC’s stories. There are no mundane PC classes. Everyone’s a mage (but usually not the squishy kind).
You’ve got your basic magic order types: Weaver, Vance, Maker, Goetic, and Apostate. But that’s only scratching the surface. A character’s forte adds a lot to character development. “Walks the Path of Sun”, “Turns Tales Into Reality”, and “Eats Knowledge” are not spells but more like career choices. The game really does revolve around magic. Everywhere.
Conflict resolution is a clever bit of narrative effort on top of stat levels. We played with very little knowledge of how to play. As long as enough of us read through the volumes to get somewhat familiar, we had a great time. Even with incomplete characters .
Thing is, at least one player really needs to at least skim through all the books (The Key, The Way, The Path, and The Gate) to get to know the game well enough to get by. The rules are scattered all over the 4 volumes. Most of the stuff is well organized, but important little bits leave you scratching your head when you can’t find the reference.
For example, there are only 3 defensive skills in the entire game: Dodge, Withstand, and Resist. However, that fact is only mentioned once in an obscure location, which I can’t find right now, and it’s not listed in the skills section. For the 1st year, we were unaware of this rule/feature.
Another example is the duration of spells PCs create, which is a very important part of being magic users. Duration is mentioned once in an odd place right after paragraphs focused on range. It’s plain as day once you know it’s there, but finding it every time we need to look it up, well… we just skip that part most of the time.
Regardless of these little oddities, our GM loves this system, as all his players do, and he’s been very hard pressed to find a system he likes to run.